128265985 has 8 divisors (see below), whose sum is σ = 159226920. Its totient is φ = 99074304.

The previous prime is 128265983. The next prime is 128265997. The reversal of 128265985 is 589562821.

It can be written as a sum of positive squares in 4 ways, for example, as 36566209 + 91699776 = 6047^2 + 9576^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128265985 - 2¹ = 128265983 is a prime.

It is a super-3 number, since 3×128265985³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (128265983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 442152 + ... + 442441.

It is an arithmetic number, because the mean of its divisors is an integer number (19903365).

Almost surely, 2^128265985 is an apocalyptic number.

It is an amenable number.

128265985 is a deficient number, since it is larger than the sum of its proper divisors (30960935).

128265985 is an equidigital number, since it uses as much as digits as its factorization.

128265985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884627.

The product of its digits is 345600, while the sum is 46.

The square root of 128265985 is about 11325.4573859072. The cubic root of 128265985 is about 504.3172618753.

The spelling of 128265985 in words is "one hundred twenty-eight million, two hundred sixty-five thousand, nine hundred eighty-five".